The DDSP autoencoder needs the input values fundamental frequency (\(f_0\) ) and loudness (\(ld\) ). Since we allow both MIDI and line-in audio, two separate implementations are needed to calculate these values. Functions for this were created in MATLAB, but in the C++ implementation we chose to use the implementation of the YIN pitch tracking algorithm [1]} from the C library Aubio[2]}, since it yielded more precise results.
